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IDProjectCategoryView StatusLast Update
0006126Talerdocumentationpublic2020-12-04 12:23
ReporterFlorian Dold Assigned ToStefan  
PrioritynormalSeveritytextReproducibilityhave not tried
Status assignedResolutionopen 
Summary0006126: consider criteria for reasonable fee structures and deriving summarizing metrics
DescriptionThis could both be beneficial for customers and to exchange operators. It doesn't really make sense for any exchange to define a "EUR:10" coin, a "EUR:0.001" coin and nothing in between!

Some snipped from an email discussion related to displaying fees to the user in the wallet:

What's also still missing is some way to view the fee structure of the
chosen exchange for deposits / refreshes. Though I have no good idea
how to represent this data in a user-friendly way. Showing the actual
fee structures might be useful for developers, but IMHO no actual user
would bother to look at them, nor even know how to interpret them. It's
also very hard to break it down into some more intuitive metrics such as
percentages, as it wildly varies based on what part of the fees the
merchant covers.

(This should be a separate discussion, but I'm writing it down here so I
don't forget about it )

One (imperfect) way to break it down would be with the following two

 1. What is the "range" of money I typically would transact? This
depends on the largest and smallest denominations offered.

 2. How much does it cost you to keep money in your wallet? This would
be computed from the validity period of denominations and refresh fees.

 3. What's are the average total fees for payments (in percentage), and
what percentage of these fees can a merchant cover? (Merchants can
cover wire and deposit fees, not so much refresh fees).

So some output would be: "With the exchange,
typical transactions are between 0.001 Eur and 100 Eur. Fees for
typical transactions range from 0.1%-0.3%. Merchants can cover 90% of
these transaction fees. During one month, keeping digital cash with this
exchange costs you 0.1% on average.

Now it's very easy to argue "These numbers are useless! It depends too
much on the amounts, since we have this discrete coin structure". But a
good counterpoint to this would be that if it varies too much, the fee
structure is broken!

So maybe we can actually come up with a reasonable way to compare fees
under certain constraints, and then for exchanges that don't follow
these constraints, the wallet declares defeat and tells the user
"Warning: This exchange has a fee structure that is difficult to predict".
TagsNo tags attached.


duplicate of 0004117 assignedStefan document fee structure considerations 


Christian Grothoff

2020-10-31 16:52

manager   ~0017077

See design-documents/008-fees.rst

Issue History

Date Modified Username Field Change
2020-03-13 13:44 Florian Dold New Issue
2020-07-16 15:23 Christian Grothoff Severity minor => text
2020-10-11 21:16 Christian Grothoff Category other => documentation
2020-10-31 10:10 Christian Grothoff Relationship added duplicate of 0004117
2020-10-31 16:52 Christian Grothoff Note Added: 0017077
2020-12-04 12:23 Stefan Assigned To => Stefan
2020-12-04 12:23 Stefan Status new => assigned